Low Intelligence Linked to Heart Disease

A recent study conducted by scientists at the British Medical Research Council adds low IQ to the short list of known risk factors for cardiovascular disease.

The results of a large study published in the February issue of the European Journal of Cardiovascular Prevention and Rehabilitation show that low IQ is second only to smoking as a predictor of heart disease.

Researchers used data collected by the British Medical Research Council over a 20-year period. The study examined the height, weight, blood pressure, smoking habits, physical activity, education, and occupation of 1145 middle-aged men and women. A standard test of general intelligence was given to each participant to measure cognitive ability.

Statistical analysis revealed smoking as the leading cause of death by cardiovascular event. Low IQ ranked second and was more strongly linked to heart disease than low income, high systolic blood pressure, or low physical activity.

Although the study was not designed to determine the reasoning behind the link, its findings invite numerous hypotheses. Some researchers believe that low IQ is a marker of difficulties experienced over a lifetime by people burdened with poverty, illness, and poor nutrition. Conversely, high IQ may be a hallmark of bodies that function better inherently. David Batty, the study’s lead investigator, suggests that perhaps “a high IQ is associated with better overall physical and mental well-being. That is, many body systems, from brain to heart to liver to kidneys, function at a more efficient level.”

Patients with a lower intelligence rating were also less likely to associate risky behaviors, such as smoking or sedentary lifestyles, with negative health outcomes. In light of these findings, Batty advises health care officials to consider IQ when drafting public health messages in order to reach as many people as effectively as possible.